Implementation of Key-aggregate Cryptosystem with Steganography For Secured Data Sharing in Cloud Computing

Cloud computing is vast developing technology, the challenging problem is how to effectively share an encrypted data in cloud computing. Data owner create an account in the cloud server and then generate the public/master secret key pair. The data and data index are encrypted by the data owner. This encrypted file is hidden into an image by using steganography and then uploaded in the cloud server. The data owner can release a constant-size Aggregate key for flexible choices of cipher text set in cloud storage, but the other encrypted files outside the set remain confidential.